def f3():
    print("---f3()start-----")
    print(10 / 0)
    print("---f3()end---")

def f2():
    print("---f2()start----")
    f3()
    print("---f2()end---")

def f1():
    f2()

f1()
# print("---f2()start----")
# print("---f3()start-----")
